[From: ] [author: ] [Date: 11-05-25] [Hit: ]
c) well you have the answer to b), just multiply how many kWhours you used (72kWh) times the price per hour ( $0.work is defined as energy per unit time, so one Watt = 1 joule per second,...... When you pay your electricity bill, you are charged not for power but for the energy used. The unit for measuring the energy used is the kilowatthour (kWh). (a) How many joules are there in one kWh? (b) How much energy, in kWh, does a 400-W TV set use in a month (30 days), if it is used an average of 6.0 h each day? (c) If electrical energy costs$0.06 /kWh, what will it cost you to operate the TV set for one month?

the answers are: (a) 3.6 x 106 J (b) 72 kWh (c) $4.32 i need to know how to do this question, please explain each step thankyou so much!!! =D - 1 kilowatt hour = 3 600 000 joules (or 3.6 x 10^6), so really you just multiply b) 400W times 30 days of 6 hours each = 400*30*6 = 72000 kWH (just multiply kW times hour to get kW hour lol ) * SORRY in case you read this part already, one correction, 72 kWh OR 72000 Wh, sorry not 7200kWh, the extra k is a mistake! c) well you have the answer to b), just multiply how many kWhours you used (72kWh) times the price per hour ($0.06)

sorry in hindsight I didn't explain part a properly :
work is defined as energy per unit time, so one Watt = 1 joule per second, therefore 1 kW = 1000 joules per second
now 1 kWh = 1 kW times 1 hour (or 3600 seconds) = 1000 joules per second times 3600 seconds = 3600000 joules
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